7 citations · 11 across the 3 of their papers we have counts for
6 papers · 1 filter
Spectral radius and clique partitions of graphs
Jiang Zhou, Edwin R. van Dam
We give lower bounds on the size and total size of clique partitions of a graph in terms of its spectral radius and minimum degree, and derive a spectral upper bound for the maximu…
Unit gain graphs with two distinct eigenvalue and systems of lines in complex space
Pepijn Wissing, Edwin R. van Dam
Since the introduction of the Hermitian adjacency matrix for digraphs, interest in so-called complex unit gain graphs has surged. In this work, we consider gain graphs whose spectr…
Trees with a large Laplacian eigenvalue multiplicity
S. Akbari, E. R. van Dam, M. H. Fakharan
In this paper, we study the multiplicity of the Laplacian eigenvalues of trees. It is known that for trees, integer Laplacian eigenvalues larger than are simple and also the mu…
The negative tetrahedron and the first infinite family of connected digraphs that are strongly determined by the Hermitian spectrum
Pepijn Wissing, Edwin R. van Dam
Thus far, digraphs that are uniquely determined by their Hermitian spectra have proven elusive. Instead, researchers have turned to spectral determination of classes of switching e…
Distance-regular Cayley graphs with small valency
Edwin R. van Dam, Mojtaba Jazaeri
We consider the problem of which distance-regular graphs with small valency are Cayley graphs. We determine the distance-regular Cayley graphs with valency at most , the Cayley…
Dual concepts of almost distance-regularity and the spectral excess theorem
Cristina Dalfó, Edwin R. van Dam, Miquel Angel Fiol +1
Generally speaking, `almost distance-regular' graphs share some, but not necessarily all, of the regularity properties that characterize distance-regular graphs. In this paper we p…